1. Field of the Invention
This invention relates to a solvent recovery process and to a solvent recovery process which provides heat recovery processes.
The invention also relates to apparatus for carrying out such processes.
2. Description of the Prior Art
Disposal of chemical wastes and recovery of useful components thereof is a significant environmental problem.
Such chemical wastes include sludge waste which is the still bottoms from the distillation of washings from liquid solvent paint wastes, adhesive wastes and printing ink wastes. Typically such wastes will include organic solvent, water and resins including synthetic resins, polymers and copolymers and inorganic solids.
In the past, still bottom sludges have been disposed of by hauling to a waste disposal site or by incineration. Incineration resulted in emissions which may be damaging to the environment and, in some cases, exceed environmental standards set by Government. Dumping in a disposal site may result in ultimate leaching of the sludge into aquifers, or water courses.
There have been attempts to recover the solvents from still bottoms. One prior proposal employs a double drum dryer, however, this suffers the problem that the residue sticks to the drum and makes continuation of the process difficult.
A further roadblock to recovery of products of value from the waste by prior processes is the high cost of recovery, and the low value of recovered solvent compared to the price of virgin solvent on the market.